From 97b79b8025b7eaab84355189110037b4a5e1eee5 Mon Sep 17 00:00:00 2001
From: Matej Focko <me@mfocko.xyz>
Date: Sun, 10 Nov 2024 19:16:43 +0100
Subject: [PATCH] =?UTF-8?q?kt:=20add=20=C2=AB3097.=20Shortest=20Subarray?=
 =?UTF-8?q?=20With=20OR=20at=20Least=20K=20II=C2=BB?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

URL:	https://leetcode.com/problems/shortest-subarray-with-or-at-least-k-ii/
Signed-off-by: Matej Focko <me@mfocko.xyz>
---
 kt/shortest-subarray-with-or-at-least-k-ii.kt | 54 +++++++++++++++++++
 1 file changed, 54 insertions(+)
 create mode 100644 kt/shortest-subarray-with-or-at-least-k-ii.kt

diff --git a/kt/shortest-subarray-with-or-at-least-k-ii.kt b/kt/shortest-subarray-with-or-at-least-k-ii.kt
new file mode 100644
index 0000000..ecfe498
--- /dev/null
+++ b/kt/shortest-subarray-with-or-at-least-k-ii.kt
@@ -0,0 +1,54 @@
+class Solution {
+    private data class Window(val bits: IntArray, var left: Int) {
+        fun updateBits(
+            number: Int,
+            d: Int,
+        ) = bits.indices
+            .filter { number.shr(it).and(1) != 0 }
+            .forEach {
+                bits[it] += d
+            }
+
+        fun toInt(): Int =
+            bits
+                .mapIndexed { index, it ->
+                    when {
+                        it != 0 -> 1.shl(index)
+                        else -> 0
+                    }
+                }
+                .reduce(Int::or)
+
+        fun update(
+            nums: IntArray,
+            k: Int,
+            right: Int,
+        ): Int {
+            updateBits(nums[right], 1)
+
+            var minLength = Int.MAX_VALUE
+            while (left <= right && toInt() >= k) {
+                minLength = listOf(minLength, right - left + 1).min()
+
+                updateBits(nums[left], -1)
+                left += 1
+            }
+
+            return minLength
+        }
+    }
+
+    fun minimumSubarrayLength(
+        nums: IntArray,
+        k: Int,
+    ): Int {
+        val window = Window(IntArray(32), 0)
+
+        return nums.indices
+            .map {
+                window.update(nums, k, it)
+            }
+            .filter { it < Int.MAX_VALUE }
+            .minOrNull() ?: -1
+    }
+}